Circuit controlling device



Dec. 19, 1939. H. OBERGFELL 2,184,101

' cIxduIT CONTROLLING DEVICE Filed Feb. 28, 1938 2 Sheets-Sheet 1 J'NduLArm/v 4 INVENTOR. HERBERT F. OBERGFELL.

ATTORNEY5.

Dec. 19, 1939. H. F. OBERGFELL.

CIRCUIT CONTROLLING DEVICE 2 Sheets-Sheet 2 .EEMMO 00% Filed Feb. 28, 1938 INVENTOR. HERBE RT F. OBERGFELL BY I z 7 t g i E Z a ATTORNEYS.

Patented Dec..1,9 ,1939

UNITED. STATES". PATENT orrics CIRCUIT CONTROLLING DEVICE Herbert r. Ob'ergiell, River Forest, 111., aslignor to Associated Electric Laboratories, Inc., Chicago, 11]., a corporation of Delaware 1 .Application February 28, 193s, Seriallio. 192,900

Claims. (01. 2005-105) character is disclosed in United States Patent No.

2,057,911, Herbert F. Obergfell, granted October 20, 1936. This device comprises a movable contact set including a pair of cooperating contact members having open and closed contact positions, a movable element for mechanically controlling the contact position of the pair of cooperating contact members, a first mechanism opergo able to move the contact set, and a second mechanism operable to move the control element. The two mechanisms are of the stepping type and are operated in response to different predetermined sequences of operations which are to be corregs 'lated with respect to .their numerical values.

These mechanisms include ratchet wheels individual thereto, the ratchet wheels having the same number of equally spaced-apart teeth. The contact set comprises a rotatable structure which so is moved from a start position step-by-step about an axis by the first'mechanism. The control element is carried by a rotatable shaft which is moved from a start position step-by-step about the same axis by the second mechanism. The

35 contact set and the control element are so constructed and arranged that the pair of cooperating contact members occupies an open contact position when the contact set and the control element occupy their start positions; that the 40 pair of cooperating contact members occupies a closed contact position when the contact set is advanced any predetermined number of steps from its start position and with respect to the control element, and that the pair of cooperating 45 contact members again occupies an open contact position when the control element is advanced this same predetermined number 01 steps from its start position.

In, this circuit controlling device, it the first 50 sequence of operations which causes the operation of the first mechanism comprises a number of operations whichexceeds the number of teeth in the ratchet wheel in the first mechanism, the contact set is advanced step-by-step from its 55 start position through 360 degrees back to its start position and then to some new advanced position corresponding to a relatively few teeth of 'the ratchet wheel. For example, if the first sequence of operations comprises fifty-two operations and there are flity teeth in. the ratchet 5 wheel in the first mechanism, the contact 'setwill occupy a position displaced a distance correspending to two teeth of the ratchet wheel from its start position at the termination of the first;

sequence of operations. Obviously, the contact 10. set will occupy this same position if the first sequence of operations comprises only two operations. Moreover, this circuit controlling device is so constructed and arranged that it is capable of controlling only one device in accordance with 15 'the correlated numerical values of the predetermined sequences of operations.

Accordingly, it is an object of the present invention to provide an improved circuit controlling I device of the, type "described which embodies an arrangement for' preventing the contact set thereof from being advanced from its start position forwardly and then back through its start position.

Another object of the invention is to provide an improved circuit controlling device of this character which is so constructed and arranged that it is capable of controlling, in a predetermined order, the operations of a plurality of devices in accordance with the correlated numerical values so of predetermined sequences of operations.

It is a further and more specific object of the invention to provide an improved circuit controlling device oi this character which is of simple construction, which comprises a minimum 35 number of parts, and which is completely reliable in operation.

In general, the objects as set forth above are attained in accordance with the present invention by providing in a circuit controlling'device of the 40 character described a movable contact set ineluding a pair of contact members having open and closed contact positions, means including a movable element for mechanically controlling the contact position of the pair of contact members of the contact set, means for moving the contact set, means for moving the control element, and

means responsive to the movement of the contact set to a predetermined position for preventing further movement thereof. More specifical- 7 ly, in the circuit controlling device, there are provided a first motor operable to rotate the contact set step-by-step about an axis, and a second motor operable to rotate the control element stepby-step about the same Also, the means responsive to the movement of the contact set to a predetermined position for preventing further movement thereof includes an arrangement for arresting the operation of the first motor. The last-mentioned means positively prevents the contact set from being advanced from a start position forwardly and then back through the start position.

In accordance with a further feature of the invention, the circuit controlling device is so constructed and arranged that it is capable of controlling, in a predetermined order, the operations of a plurality of devices in accordance with the correlated numerical values of predetermined sequences of operations. Specifically, the movable contact set includes a plurality of pairs of cooperating contact members, each of the pairs of cooperating contact members of the contact set having open and closed contact positions, and means including a movable element for controlling the contact positions of the pairs of cooperating contact members of the contact set. The contact set and the control element are so constructed andarranged that 'a first pair of cooperating contact members occupies a predetermined one of the contact positions only when the contact set and the control element occupy their start positions and positions displaced equal distances from their start positions, and that a sec-.- ond pair of cooperating contact members occupies a predetermined one of the contact positions only when the contact set and the control element occupy their start positions and positions displaced less ,than a predetermined distance from each other.

Thenovel features believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the specification, taken in connection with the accompanying drawings, in which Fig. 1 is a side [elevational view of a circuit controlling device vice.

Referring now more particularly to Figs. 1 and 2 of the drawings, the circuit controlling device there illustrated comprises a supporting frame it provided with spaced-apart side members H in which the opposite ends of a transversely extending rotatable shaft l2 are iournaled. A structure comprising a group of slip rings l3, a first member or contact set M and a ratchet wheel- I 5 is rotatably mounted upon the shaft I2 be-- tween the sidemembers I I; and a second member or control element l6 and a ratchet wheel II are securely fastened to the shaft l2 between the side members ll'.

The group of slip rings 13 comprises the slip rings l3, I3, and 2|, which are electrically insulated from each other and from the remainder of the structure by an arrangement including a plurality of insulating members 22 disposed between the slip rings. A group of brushes or collectors23, 24, 26 and 26 are associated with the slip rings l3, I3, 26 and II,- respectively. and

serve to extend electrical connections thereto. The brushes 23, 24, 26 and 26 are carried by an insulating terminal block 21 secured tothe supporting frame [0 of the device and are connected to corresponding outgoing conductors; The contact set l4 comprises aplurality of pairs of cooperating contact members 28, 29 and 30, each of the contact members of each pair being formed of fiexible spring metal and carrying an electrical contact formed of. platinum or other are resisting material. The cooperating contact members of each pair are electrically insulated from each other, from the contact members of adjacent pairs, and from the remainder of the structure'by an arrangement including a plurality of insulating members 3i disposed between the contact members. The cooperating contact members of each pair are biased toward each other in order to bring the electrical contacts carried thereby into engaged relation or closed contact position, and are capable of being moved away fromeach other in order to bring the electrical contacts carried thereby into disengaged relation or open contact position. As best shown in Fig.4, a circuit arrangement is provided including a conductor 50 for connecting the right-hand contact member of each of the pairs of cooperating contact members 28, 29 and 30 to the slip ring l8, and including conductors 5|, 52 and 53 for connecting the left-hand contact member of each of the pairs 'of cooperating contact members it, 29 and 30, respectively, to the slip rings I9, 26 and 2|, respectively.

The control element l6, as best shown in Figs.-

2 and 3, comprises two transversely extending arms 32 and 32 to which are respectively secured two cylindrical insulating members 33 and 34, and between which is secured an arcuate shaped insulating member 35. Theinsulating members 33, 34 and 35 are associated, respectively, with the .pairs of cooperating contact members 28, 29 and 30, each insulating member being adapted to be brought between the cooperating contact members of the associated pair in order to move the cooperating contact members away from each other, thereby to move the electrical contacts carried by the cooperating contact members fromclosed contact position into open contact position.

The structure comprising the group of slip rings l3, the contact set l4 and the ratchet wheel I5 is rotated as a unit step-by-step about the shaft I2 by a first mechanism 36; and the shaft i2 carrying the control element l6 and the ratchet wheel I! is rotated step-by-step in the bearings formed inthe side members I I by a second mechanism 31. The mechanism 36 is of the stepping type and essentially comprises a motor magnet 38, an armature 39, a pawl 40, the ratchet wheel l5 and a holding detent 4|. The mechanism 31 is of the same construction and includes a motor magnet 42 and the ratchet wheel IT. The mechanical construction of these stepping mechanisms may be substantially the same as that disclosed in United States 'Patent No. 1,794,888, John Erickson, granted March 3, 1931. Each of the ratchet wheels I5 and I1 comprises the same number of equally spaced-apart teeth, and for purposes of illustration it is assumed that each of these ratchet wheels comprises fiftybe rotated one step in a clockwise direction, as 7 viewed in Fig.1, about the axis of the shaft I2;

and upon each operation .01 the stepping mechanism 31. the shaft -l2 carrying the control element l6 will be rotated one step in a clockwise direction about this same axis. i

The contact set l4 and-the control element l8 occupy the initial or start positions illustrated in Figs. 3 and 5, when the device is in a non-operated condition, these positions of the contact set and the control element with respect to each other constituting a synchronous position. When operation of the device is initiated, the contact ,set 4 is first rotated a predetermined number of steps in a clockwise direction from its start position, thereby causing the pairs of cooperating contact members to be moved in a predetermined order fromone contact position to the other.

set M and the control element ii are so con-;

structed and arranged that, when the contact set 14 and the control element l6 occupy their initial orstart positions, the insulating member 33, is disposed one step behind or forty-nine steps ahead of the associated, pair of cooperating con.- tact members 28, the insulating member 34 is disposed between the associated pair of cooperating contact members 28, and the rear end of the insulating member 36 is disposed between the associated pair of cooperating contact members 30. Thus, in the start positions of the contact set I4 and the control element i6, th pair of cooperating contact members 28 occupies its closed contact position, and the pairs of cooperating contact members 28 and occupy their open contact positions. The cylindrical insulating members 33 and 84 are formed having a diameter which is so proportioned with respect to the distance moved by the associated pairs of cooperating contact members 28, and 28 that the insulating member 34 is .removed from between the associated pair of .cooperating contact members 28 uponthe first step of the contact set l4 from its start position; and that the insulating member 33, when disposedbetween the asso-' ciated pair of cooperating contact members 28,

is removediromtherebetween upon the first step of the control element I8 from its start position.' The arcuate shaped insulating member 35 is formed having alength such that this insulating member is disposed between the associated pair of cooperating contact members "during a predetermined number of steps ofthe contact set i4 from its start position. For purposes of illustration it is assumed that the insulating member 38 is formed having a length such that this insulating member rema i'ns in its position disposed between the associated pair'of cooperating contact members 38 during the first thirteen steps oi. the contact member I 4 from its start position. Thus it will be apparent that, when the contact set I4 is advanced any number of steps between one and thirteen from its start position, the insulating "member 33 .is disposed ahead of the associated pair of cooperating contact members 28, the in teenth positions of the contact set ,ircm its start'position, the pairs oi cooperating contact members 28 and 28 occupy their closed contact siiltions and the pair of cooperating contact e bers 30 occupies its open contact position.

When-the contact set M is advanced into its fourteenth position from its start position, the insulating member is removed from between the associated pair of cooperating contact members 38. Accordingly, in this position 0! the contact set l4, each of the pairs ofcooperating contact'members 28, 28 and 38 occupies its closed contact position; If, the contact set l4 should be advanced into its forty-ninth position from its start position, which position is only one step behind its start position, the insulating member. 83 is brought between the associated pair of cooperating contact members 28, thereby mov-,

ing this-pair oi cooperating contact members ..into its open contact position. as will be more fully described subsequently, the pair of coopcrating contact members 28 is included in a circuit for controlling the energization of the motor magnet 38 of the stepping mechanism 36, which mechanism causes the contact set 14 to be rotated from its start position. Thus, when the contact set. i4 is advanced into its forty-ninth position from its start position, the circuit for controlling the energization of the motor magnet 38 is interrupted, therebyarresting the operation of the motor magnet 38 and positively preventing the contact set H from being advanced into its fiftieth or start position. The control element I8 is then advanced step-by-step .from its start position by the motor magnet 42.

As the control element I6 is advanced from its start position, the insulating member 33 is disposed ahead of the associated pair of cooperating contact members 28 and the insulating members 34 and 35 are disposed behind the associated pair of cooperating contact members 28 and 38 until the control element i6 is'moved a prede-, termined number of steps from its start position or into a position disposed thirteen steps behind the position of the contact set l4, at

which time the insulating member 35 is moved between the associated pair of cooperating contact members 38. Thus, the associated pairs of cooperating contact members'28, 29 and 30 remain in closed contact positions until the control element l6 is advanced to a position disposed thirteen steps behind the position ofthe contact set N, at which 'time the pair of cooperating contact members 38 is moved to its open contact position.- The pairs of cooperating contact mem- .bers 28 and 29 remain in their closed contact positions and the pair of cooperating contact members 30 remains in its open contact position until the control element I8 is advanced into. a' position corresponding to the position of the contact set I4, at which time a. new synchronous.

position is established and the pair of cooperatLng contact members 28 is moved to its open contact position. These positionsof the contact member i4 and the control element l8 constitutestart positions for the contact member l4 and the element I6 upon each operation of the device.

Reterring now more particularly to Fig. 5,

there is diagrammatically illustrated a practical circuit arrangement utilizing a circuit con-- trolling device of the construction described for controlling the operations of the two devices 43 and 44, the circuit controlling device being'connected and arranged to correlate with respect to numerical values a first,predetermined sequence of operations of an impulsing device 48 with a related second predetermined sequence of operations of an impulsing device 48. In this arrangement there are provided circuits for controlling individually the energization of the motor magnets 88 and 42 of the circuit controlling device, and circuits for controlling individually the operations of the devices 4 and .44. The circuit for controlling the energization of the motor magnet 88 extends from one terminal or a grounded battery, not shown, by way of contacts included in the impulsing device 48, the winding of the motor magnet 38, a conductor 84, the slip ring IS, the conductor II, the pair of cooperating contact members 28, the conductor 58, the slip ring l8, and the conductor 58 to ground. The circuit for controlling the energization or the motor magnet 42 extends from one terminal of grounded battery, by way oi contacts included in the impulsing device 4 48, the winding of the motor magnet 42, a conductor 56, a conductor 58, the slip ring", the conductor 82, the pairroi cooperating contact members 28, the conductor 88, the slip ring l8, and the conductor 55 to "ground. The circuit for controlling the operation of the device 48 extends irom one terminal of grounded battery, by way of the device 43, aconductor 81, theslip ring 2|, the conductor 53, the pair of cooperating contact members 88, the conductor 88, the

, slip ring l8, and the conductor 55 to ground;

and the circuit for controlling the operation of the device 44 extends from one terminal of grounded battery by way of the device 44, a conductor 56, the conductor 58, the slip ring 20, the conductor 52, the pair of cooperating contact members 28', the conductor 50, the slip ring 18, and the conductor 88 to ground.

During the operation of the arrangement, and when the contact set l4 and the control element I8 of the circuit controlling device occupy their initial or start positions, the above-traced circuits for controlling the energization of the motor magnets 38 and 42 are respectively interrupted at the contacts included in the impulsing device 48, and at thecontacts included in the impulsing device 48 and the pair of cooperating contact members 28; while the above-traced circuits for controlling the operations or the devices 48 and 44 are respectively interrupted at the pairs of cooperating contact members 88 and 28. Upon a. first predetermined sequence of operations, the impulsing device 48 operates repeatedly to close and open the contacts included therein a corresponding number of times, thereby to complete and interrupt a corresponding number oi times the circuit for controlling the energization of the motor magnet 38, whereupon the contact set is rotated step-by-step a corresponding number of steps or to a corresponding position disposed from its start position. For example, it the first, predetermined circuit for controlling the energization of the motor magnet 42 is prepared at the pair of cooperating contact members 28, this circuit being interrupted at this time at the contacts included in the impulsing device 4!. Upon the rotation of the contact set l4 into its fourteenth position PM, the circuit for controlling the operation of the device 48 is completed at the pair of cooperating contact members 80, and the device 43 is operated. The devices 43 and 44 remain operated during the remainder of the rotation of the contact set l4 to its forty-eighth position P48, whereupon the circuit for controlling the energization of the motor magnet 38 is interrupted at; the contacts included in the impulsing device Upon a second predetermined sequence of operations, the impulsing device 46 operates repeatedly to close and open the contacts included therein a'corresponding number of times, thereby to complete and interrupt a corresponding number of times the circuit for controlling the energization of the motor magnet 42, whereupon the control element I8 is rotated step-by-step a corresponding number ofsteps or to a corresponding position disposed from its start posisequence of operations comprises forty-eight "operations, the control element I6 is rotated to its forty-eighth position P48 from its start position P88, Upon the rotation of the control element l8 into its thirty-fifth position, the circuit for controlling the operation of the device 48 is interrupted at the pair of cooperating contact members 80, causing interruption of the operation oi the device 43; and, upon the rotation of the control element l8 into its fortyeighth position, the circuit for controlling the operation of the device 44 is interrupted at the pair of cooperating contact members 29, causing interruption of the operation of the device 44. Thus. the device 44 is operated thirteen steps before the device-42 is operated, and the device 44 remains operated thirteen steps after the operation of the device 41 is interrupted.

Also, when the control element I8 is rotated the same number oi steps from its start position as the contact set N has been rotated from its start position, or the control element "5 is rotated to a position corresponding to the' position of the contact set l4, further rotation of the control element I6 is arrested regardless of the continued operation of the impulsing device 46, as the circuit for controlling the energization of the motor magnet 42 is interrupted at' the pair the control element I8 is rotated from its start position a number of steps corresponding to the number of operations of the second predetermined sequence or operations, provided the number of operations of the second predetermined sequence of operations does not exceed the number of operations 0! the first predetermined sequence of operations. In case the number of operations of the second sequence exceeds the number of operations of the first sequence, the element i8 is rotated from its start position a number of steps corresponding to the number of operations of the first sequence. This arrangement prevents the control element l8 from being advanced ahead of the contact set N, and the consequent disturbance of the predetermined order of operations of the device 43 and 44.

Also, the contact set I 4 and the control element l8 are so constructed and arranged that the contact set I4 is prevented from being rotated from its start position forwardly and back through its start position. For example, it the first predetermined sequence of operations comprisesmore than forty-nine operations, the con-. tact set M is rotated only to its forty-ninthposition P48, at which time further rotation oi the contact set M is arrested, regardless of the conthe contact set is rotated from its start position into its forty-ninth position From the foregoing description it will be ap parent that a circuit controlling device is provided, which includesan arrangement tor correlating with respect to numericalvalues a first.

her to establish a newsynchronous position predetermined sequence of operations with a related secondpredetermined sequence of operations, and which is adapted to control, in a predetermined order; the operations of a plurality of devices in accordance with the correlated numerical values. a

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein without departing from the invention, and it is intended in the appended claims to cover all such embodiments as fall within the true spirit and scope'ot the invention.

What is claimed is: f- 1. In a cyclically operating circuit controllin device, first and second members independently movable in the same direction along a common path, said members having a synchronousposb tion with respect to each other which may occur at any point along. said path, circuit controlling contacts controlled jointly by. said members and closed when said members occupy a predeter mined position with respect to-each other, means for moving said first member away from a synchronous position, thereby to initiate a cycle of operation, means for arresting .further movement of said first member after a predetermined movement thereof away from any synchronous position, means for moving said second mem thereby to complete the cycle of operation, and means for positively arrestingfurther movement of said second member when a new synchronous position is established. J A

2. In a cyclically operating'circuit:controlling movable in the same direction along a common a path, said members having a synchronous posi-' tion with respect to each other which may occur at any point along said path, circuit con-' trolling contacts controlled jointly by said mem-" bers-and closed when said members occupy a predetermined position with respect to each other, means including a first motor operable to a move said first member away from a synchronous position, ther by to initiate a cycleof 'operation',-means for arresting further operation .of said first motor after'a predetermined movement of said first member away from any synchronous position, means including asecond motor operable to move said second member to "i-otatable step establish. a new synchronous position, thereby to complete the cycle of operation, and means forpositively arresting further operation of said sec- -ond motorwhen. a new synchronous position is established.

3. ma cyclically operating circuit controlling device, first and second members independently movable'step by step in the same direction along a common path, said members having a synchronous position with respect to each other which may occur at any step along said path,

circuit controlling contacts controlled jointly by said members and closed when said member-soccupy a predetermined positionwith respect to each other, means for movingsaid first meal-- ber step by step away from a synchronous posi-.

tion, thereby to'initiate a cycle of operation, means for arresting further movementoi. said first member after said first member is moved a predetermined number of steps away from any synchronous position, means for moving said sec-- ond member step by step to establish a new synchronous position, thereby to complete the as of operation, and means for positively arresting further movement of said second member when a new synchronous position is established.

4. In a cyclically operating circuit controlling device, first and second members independently rotatable in the same direction about a common axis, said members having a synchronous position with respect to each other which may occur at any angular position, circuit controlling contacts controlled Jointly by said members and closed when said members occupy a predetermined position with respectto each other, means for rotat-- ing said first member away from a synchronous position, thereby to initiate a cycle of operation, means for arresting further rotation of said first member after a predetermined rotation thereof away from any synchronous position, means for rotating said second member to establish a new synchronous position, thereby to complete the cycle of operation, and means for positively arresting further. rotation of said second member when a new synchronous position is. established.

5. In a cyclically operating circuit controlling device, first and second membersindependently by step inthe same direction about a common axis, said members having a synchronous position with respect to each other which may occur at any angular step, circuit controlling contacts controlled jointly by said members and closed when said members occupy a predetermined position with respect to each other, means including a first motor operable to rotate chronous position, thereby to initiate a cycle of operation, means for arresting further opera= device, first and second members independently 'iurther operation or said second motor when a new synchronous position is established.

"6. In a cyclically, operating circuit-controlling device, first and second members independently movable in the same direction along a common path, said members having a synchronous posi- "tion with respect to each other'which may occur at any "point along said'path, a plurality 01 pairs or circuit controlling contacts controlled jointly by said members, each of said pairs oi! contacts havingopen and closed contact positions, means for moving said first member away from a synchronous position, thereby to initiate a cycle of operation, means for moving said second member to establish a new synchronous position, thereby to complete the cycle of operation, said members being so constructed and arranged that a first pair of contacts occupies a predetermined one of said contact positions only when said members occupy synchronous positions and that a second pair of contacts occupies a predetermined one of said contact positions only when said first member is moved a predetermined distance away from any synchronous position, means controlled by said second pair of contacts for arresting further movement of said first member after said first member is moved said predetermined distance away from any synchronous position, and means controlled by said first pair of contacts for arresting further movement'of said second member when anew synchronous position is established.

7. In a cyclically operating circuit controlling device, first and second members independently. movable in the same direction along a common path, said members having a synchronous position with respect to each other which may occur at any point along said path, a plurality of pairs of circuit controlling contacts controlled jointly by said members, each of said pairs of con- I tacts having open and closed contact positions, means including a first motor operable to move said first member away from a synchronous position, thereby to initiate a cycle of operation,=

means including a second motor. operable to move said second member to establish a new synchronous position, thereby to complete the cycle of operation, said members being so constructed and arranged that a first pair of contacts cupies an open contact position only when said members occupy synchronous positions and thata second pair of contacts occupies an open contact position only when said first member is moved a predetermined distance away from any synchronous position, an operating circuit for said first motor including said second pair'oi.

tion with respect to each other which may occur at any point along said path, a plurality of pairs of circuit controlling contacts controlled jointly by said members, each of said pairs of contacts having open and closed contact positions, means for moving said first member step by step away from a synchronous position, thereby to initiate a cycle of operation, means for moving said second member step by step to establish a new synchronous position, thereby to complete the cycle of operation, said members being so constructed and arranged that a first pair of contacts occupies a predetermined oneoi! said contact positions only when said members oc cupy synchronous positions and that a second pair of contacts occupies a predetermined one of said contact positions only when said first member is moved a predetermined number of steps away from any synchronous. position, means controlled by said second pair of contacts for arresting Iurther movement oi said first member after said first member 3 5 means including a-first motor operable to rotate predetermined number of steps away from I synchronous position, and means controlled by said first pair of contacts for arresting further movement of said second member when a new synchronous position is established.

9. In a cyclically operating circuit controlling device, first and second members independently rotatable step by step in the same direction about a common axis, said members having a synchronous position with respect to each other which may occur at any angular step, a plurality of pairs oi. circuit controlling contacts controlled Jointly by said members, each of said pairs of contacts having open and closed contact positions,

said first member step by step away from a synchronous position, thereby to initiate a cycle of operation, means including a second motor operable to rotate said second member step by step to establish a new synchronous position, thereby to complete the cycle oi dperation, said members being so constructed and arranged that a first pair of contacts occupies a predetermined one. 01 said contact positions only when said members occupy synchronous positions and that a second pair' of contacts occupies a predetermined one of said positions only when said first member is rotated a predetermined/number oi steps away from any synchronous position, means controlled by said second pair 01' contacts for arresting further operation of said first motor aitersaid first member is rotated said predetermined number oi. steps away from any synchronous position, and means controlled by said first pair of contacts for arresting further operation of said second motor when a new syn.-

chronous position is established.

10. In a cyclically operating circuit controlling device, first and second members independently movable'in the same direction along a common path, said members having a. synchronous position with respect to each other which may occur at any point along said path, a plurality oipairs of circuit controlling contacts controlled Jointly by said members, each oi' said pairs oi. contacts having open and closed contact positions, means for moving said first member away from a synchronous position, thereby to initiate a cycle of operation, means for moving said second member to establish a new synchronous position, thereby to complete the cycle oi operation, said members being so constructed and arranged that a first pair of contacts occupies a predetermined one oi! said. contact positions only when said members occupy synchronous positions and that a secondpair 01' contacts occupies a predetermined one oi said contact positions only when said-first member is moved a predetermined distance away from any synchronous position and that a third pair of contacts occupies a predetermined one oi said contact positions only when said members occupy synchronous positions and positions displaced less than a predetermined distance from synchronous positions, means controlled by said second pair of contacts for arresting further movement or said first member when said first member is/moved said predetermined distanceaway from any synchronous position,

means controlled by said first pair 01' contacts for arresting further movement of said second 70 T I. OBERGFIIL; 

